Stephen Hornsby has practised EU and UK competition law as an enforcer, in house lawyer, and as a solicitor in private practice for national, City, and West End firms since 1983. At the European Commission he wrote the British Leyland pricing abuse decision and initiated the proceedings in the Hilti and UK Net Book cases – all of which were upheld on appeal in the European Court of Justice. In private practice, he brought the first wholly successful judicial review challenge against the Office of Fair Trading under the Competition Act 1980 on behalf of Stagecoach. This legislation was replaced by the Competition Act 1998 and he brought the first successful injunction application under this legislation on behalf of a new entrant; this decision, which enabled entry to take place unimpeded by the dominant firm in a digital services market, was upheld in the Court of Appeal.
For the last twenty years he has been particularly involved in the controversial application of competition law in the culture, media and sporting sectors – acting most recently for the leading model agencies in the CMA investigation and in a challenge to the rules of a sporting organisation restricting salaries in a sport employment market. He has written extensively on these matters himself and has also co-authored a textbook on the Competition Act 1998 and an influential article on leniency application policy.